vi.] ABOUT A FERN. 103 



thallus develops reproductive organs which, instead of 

 producing other prothalli, give rise to a true fern like 

 that which produced the spore. In this lies its chief 

 difference from a seed, for a seed produces a plant 

 exactly resembling that which produced the seed. 



And now it grows vigorously and sends up frond 

 after frond, until the stem becomes thick and the 

 fronds long and spreading, and bear upon their under- 

 surface spore clusters, like those we have before 

 alluded to. These spores afford the surest method 

 to the tyro for detecting ferns, as no other plants 

 produce spores in the same manner. The leafy 

 portion of the fern is known as a frond, but it differs 

 considerably from the leaves of flowering plants. In 

 the latter the point, or apex, of the leaf is first formed, 

 the leaf-stalk last. In the fern the leaf-stalk is formed 

 first, and the apex the last. 



If we examine a growing plant of the Common 

 Bracken-fern (Pteris aquilind] we shall find it to 

 consist of an underground creeping stem giving off 

 rootlets below and fronds above. In this case the 

 stem is called a rhizome, because of its creeping 

 underground, but if we take the Common Male-fern 

 (Lastrea fihx-mas) we shall find that the stem, 

 instead of taking a horizontal direction, as in Bracken, 

 is perpendicular, and the upper end is above the 

 ground. In this case the stem will be termed a 

 caudex, and a more noticeable example of it will be 

 found in the arborescent stems of the Tree-fern of 

 Australia, &c. It should be noticed that the fronds 

 arise, not from the growing point of the stem, but 

 from certain points at a greater or lesser distance 



